The field of the invention is portable, battery powered electronic equipment and, more particularly, remote receivers for laser alignment systems.
Laser alignment systems are well-known in the industry, primarily for use at construction sites. One such system has been described, for example, in U.S. application Ser. No. 788,800, filed Oct. 18, 1985, entitled "Self Levelling Transmitter For Laser Alignment Systems". In a typical application, a central transmitter projects laser light in a precise alignment cone extending 360.degree. around the transmitter. One or more receivers, including photocell detectors, are then used throughout the area to detect the alignment cone of light and indicate whether the receiver is above, below, or on the alignment cone.
The remote receiver may be battery powered and may be held by hand or mounted on a pole or on an existing structure such as a building. If the receiver is mounted on a pole or other structure, the structure may create a shadow which obstructs the light from the laser transmitter. This creates a problem in that the receiver must be moved (and perhaps mounted on another structure) in order to be directed in the direction of the transmitter. The requirement of moving the receiver in order to get an unobstructed reading impairs the usefulness of the equipment.
Also, in any portable electronic equipment, the battery must be replaced regularly. In a typical 9-volt battery compartment, the battery terminals are press fitted into mating terminals carried by a plate which is connected by wires to the housing of the electronic device. In order to insert a battery, the plate containing the terminals must be fished out of the housing, pulling the wires out so that they extend out of the housing; the battery is pressed into the mating terminals; and then the wire and battery are all pushed back into the housing. This arrangement is undesirable for several reasons. The wire leads dangling out of the housing are a nuisance, can be severed or pulled loose from the housing, and generally create opportunities for failure. In addition, the manufacture of such an electronic apparatus includes a substantial amount of labor necessary for soldering the wires to the terminals, to the housing, and so forth. Also, the door which typically covers the battery compartment is a separate member which somehow clips onto the housing. Such doors are easily lost, leaving the battery compartment open, which is undesirable.